Missing words in messagesSupport

After updating to Android 2.3.5, some words don't seem to be recognised in messages any more. I've inputted them into my personal dictionary a fair few times, but the phone still doesn't seem to know what it means, even though it has saved. I've tried a soft reboot, and don't really want to go down the hard reboot option over something so trivial. It is highly annoying!
If they were slang words, I'd understand more, but these are actual, once pre-installed words such as 'am' and 'bring'.

If someone has any ideas at all, please share, because having to type in individual letters is not the way a smartphone should work! (Not using qwerty, using standard keypad predictive text).

Did you find a solution to this? I am having the same problem with my HTC Desire HD, ever since I upgraded to 2.3.5, my autocorrect dictionary won't add some of the most basic (and frequently used!!) words like 'am' and 'at', even though it says that it does. I've also tried adding them directly to my user dictionary, still no luck. It is SOOOOOOO frustrating, I never realised how often those words are used... Would love to know if you worked out a way to address this?